β Stability and Mechanical Behavior of Metastable β Type TiNb Based Alloys

摘要

Metastable β type TiNb based alloys of Ti-35Nb, Ti-35Nb-4Sn and Ti-42Nb-4Sn (wt. %) with different stability were prepared and thermo-mechanical treatment was carried out to investigate their microstructural evolution and mechanical properties. It was found that although the TiNb based alloy with lower stability performs lower strength in its solution state due to the stress induced martensitic transformation, they could be strengthened significantly by severe cold rolling followed by aging, remaining a relative low elastic modulus. X-ray diffraction, transmission electron microscopy and mechanical test were conducted to characterize the microstructural evolution and mechanical behavior of the metastable β type TiNb based alloys with different β stability. The strengthening mechanism was discussed on the basis of the cold deformation and martensitic transformation.